altos can get to 5-6"...but there is a species called Sumbu Dwarf....ralph at archaquatics usually has the,...we had some but for some reason we lost the whole tank...but the Sumbus stay under 3 inches...
we currently have yellow....black congo....ink fin and chaitika whites.......

I have super hard water, and I use RO (reverse oasmosis) water for water changes, mixed with tap (dechlor treated, of course.) RO water is easily obtained at grocery stores--my store sells it in 3-5 gal. jugs, which are refillable and refills are cheaper. I also use a "blackwater" liquid additive that my fish love. Just be sure to use less than instructions say to the first time because it will turn the water brownish, for a while.

I think my next tank is going to be a 90 gallon south american tank if everything comes together like I am hoping... I want to do a sand bottom... Do I need to buy the sand from the pet shop or can i got to Home Depot and buy the fine play sand that seems like its about the same... Anyone here ever do this before?

check you phone book for local builders supply places that sell brick and block and such...
call and ask about the coarse builders sand.....buy extra to replace lost fine stuff and dirt...it won't be washed for you....lol....i am not fond of the fine sands although they can be used..
and the stuff from the builders supply will be a lot cheaper...all you need are a couple of home depot 5 gallon buckets and a shovel..